Branch stent graft deployment and method

ABSTRACT

A deployment system for introducing stent grafts which have a side arm or into which a side arm can be deployed. For instance the stent graft can be deployed into the thoracic arch of a patient. The deployment system including an introducer ( 1 ), an auxiliary catheter ( 13 ) disposed within the introducer and an auxiliary guide wire ( 14 ) disposed within the auxiliary catheter. The auxiliary guide wire extends to adjacent the proximal end ( 6 ) of the introducer an can be extended from the proximal end of the introducer so that it can be snared from a side branch artery ( 56 ) to assist with deployment of a side arm ( 23 ) of the stent graft into the side artery or for the deployment of a side arm stent graft into the stent graft.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional application of co-pendingnonprovisional application Ser. No. 10/818,538, filed Apr. 5, 2004,which application in turn claims priority of provisional applicationSer. No. 60/460,291, filed Apr. 3, 2003, and Ser. No. 60/510,244, filedOct. 10, 2003.

TECHNICAL FIELD

This invention relates to an endoluminal deployment system, a stentgraft for endoluminal deployment and a method of endoluminal deploymentof such a stent graft into a vessel with a side branch such as thethoracic arch of a patient.

BACKGROUND OF THE INVENTION

The invention is particularly directed towards deploying a stent graftwith a fenestration from which or into which a side arm can be deployedto enter one of the arteries that extends from the thoracic arch. Thesearteries are the innominate artery, the left carotid artery and the leftsubclavian artery. The invention will generally be discussed in relationto an endoluminal deployment system to enable branch grafting into theleft subclavian artery but the invention may equally apply to the otherarteries or to other vessels in the human or animal body.

Throughout this specification the term distal with respect to a portionof the aorta, a deployment device or a prosthesis is the end of theaorta, deployment device or prosthesis further away in the direction ofblood flow away from the heart and the term proximal means the portionof the aorta, deployment device or end of the prosthesis nearer to theheart. When applied to other vessels similar terms such as caudal andcranial should be understood.

SUMMARY OF THE INVENTION

In one form therefore the invention is said to reside in a deploymentsystem for a stent graft to be deployed into an internal lumen of apatient, the deployment system comprising an introducer with the stentgraft retained thereon, the introducer having a proximal end intended tobe deployed within a patient in use and a distal end intended to remainoutside the patient and an auxiliary guide wire, the auxiliary guidewire extending to adjacent the proximal end of the introducer wherebythe auxiliary guide wire can be extended from the proximal end of theintroducer so that it can be snared from a side artery to assist withdeployment of a stent graft into the side artery.

Preferably the introducer includes a sheath to retain the stent graft ina retracted state on the introducer.

The stent graft may be of a type which includes a side branch and theauxiliary guide wire extends through the side branch. Alternatively thestent graft can include a fenestration and the auxiliary guide wireextends through the fenestration. The Alternatively the fenestration caninclude a graft tube extending into the stent graft from thefenestration either distally or proximally.

The auxiliary guide wire can be retained in an auxiliary catheterextending to the distal end of the introducer and the auxiliary guidewire can extend out between a nose cone on the proximal end of theintroducer and a sheath on the introducer.

There may be provided a retention arrangement for the stent graft on theintroducer which is adapted to retain the proximal and distal ends ofthe stent graft onto the introducer and includes trigger wires andtrigger wire release mechanisms to release the proximal and distalretention arrangements.

Diameter reducing ties with an associated trigger wire and trigger wirerelease mechanisms can be used for the side arm stent graft, thediameter reducing ties being used to hold the diameter of the side armreduced against the force of self expanding stents in the side arm sothat it can be drawn into the side branch artery without unduly engagingthe walls of the artery.

In a further form deployment device for deploying a branched stent graftin a thoracic arch of a patient, the stent graft being of a type havinga main tubular body with a main lumen therethrough and a side arm with aside arm lumen extending therethrough, the deployment device including amain guide wire catheter extending from a proximal end to a distal end,a nose cone at the proximal end of the guide wire catheter an auxiliaryguide wire catheter with an auxiliary guide wire extending therethroughextending from the distal end to the nose cone, the stent graft beingretained on the main guide wire catheter distally of the nose cone withthe main guide wire passing through the main lumen and the auxiliaryguide wire extending through the main lumen and the side arm lumen andextending to the nose cone and the side branch being retained on theauxiliary guide wire catheter and a sheath coaxial with the main guidewire catheter and extending to the nose cone and enclosing the stentgraft.

Preferably the stent graft and side arm on the stent graft includeself-expanding stents and a tubular biocompatible graft.

In a further form the invention is said to reside in a deployment devicefor deploying a fenestrated stent graft in a thoracic arch of a patient,the stent graft being of a type having a main tubular body with a mainlumen therethrough and a fenestration in the tubular body, thedeployment device including a main guide wire catheter extending from aproximal end to a distal end, a nose cone at the proximal end of theguide wire catheter, an auxiliary catheter with an auxiliary guide wireextending therethrough extending from the distal end to the nose cone,the stent graft being retained on the main guide wire catheter distallyof the nose cone with the main guide wire passing through the main lumenand the auxiliary catheter extending through the main lumen and thefenestration and further extending to the nose cone and a sheath coaxialwith the main guide wire catheter and extending to the nose cone andenclosing the stent graft.

Preferably the stent graft is retained on the main guide wire catheterwith the side arm extending proximally from its connection point withthe main tubular body. Hence when advancing the side arm into the sidebranch artery the introducer with the stent graft retained on it isadvanced proximally to allow the side arm to enter the side branchartery.

The stent graft and side arm on the stent graft may includeself-expanding stents and a tubular biocompatible graft materialcovering the stents. The proximal stent may include barbs. There mayalso be provided at the distal end of the stent graft a distallyextending uncovered self expanding stent with barbs to retain the distalend of the stent graft in the aorta. Alternatively the stent graft maybe a proximal portion of a composite stent graft and the distal end ofthe stent graft can be adapted to be connected to or into another stentgraft.

The stent graft may have a diameter of from 30 to 40 mm and a length offrom 100 to 200 mm. The side arm may have a diameter of 10 to 15 mm anda length of from 20 to 50 mm. The self expanding stents in the main bodyof the graft and in the side arm may be Gianturco self expanding zigzagZ stents made from, for example, nitinol or stainless steel.

The deployment device may include a Y branch on the distal end thereofwith the auxiliary guide wire catheter extending out of the Y branch.There can be provided a locking arrangement to fix the auxiliary guidewire with respect to the auxiliary guide wire catheter. Alternativelythe auxiliary catheter can extend from the distal end of the handle.

In a further form the invention is said to reside in a method ofintroducing a fenestrated stent graft into the thoracic arch of apatient such that a stent graft can be deployed into the fenestrationfrom the branch artery in the thoracic arch, the method including thesteps of; (a) introducing an introducer via a femoral artery so that thefenestration is adjacent the branch artery to be grafted, (b) extendingan auxiliary guide wire from the introducer, (c) snaring the auxiliaryguide wire from the branch artery by means of a snare catheterintroduced via a brachial artery and drawing the auxiliary guide wireinto the brachial artery, (d) withdrawing the sheath from theintroducer, (e) advancing a side arm stent graft on a side armintroducer over the auxiliary guide wire into the fenestration, (f)releasing the distal and proximal ends of the stent graft, and (g)releasing the side arm stent graft from the side arm introducer. In afurther form the invention is said to reside in a method of introducinga branched stent graft into the thoracic arch of a patient such that thebranch of the stent graft is deployed into the branch artery in thethoracic arch, the method including the steps of; (a) introducing anintroducer via a femoral artery to adjacent the branch artery to begrafted, (b) extending an auxiliary guide wire from the introducer, (c)snaring the auxiliary guide wire from the branch artery by means of asnare catheter introduced via a brachial artery and drawing theauxiliary guide wire into the brachial artery, (d) inserting an arterywall protecting sleeve or catheter over the auxiliary guide wire via thebrachial artery and clamping it to the auxiliary guide wire, (e)withdrawing the sheath from the introducer, (f) advancing the introducerproximally and drawing the side arm into the side branch artery usingthe artery wall protecting sleeve or catheter and the auxiliary guidewire, (g) releasing the distal and proximal ends of the stent graft, (h)releasing the diameter reducing ties on the side arm in the side branchartery, and (i) removing the introducer.

If necessary and depending upon the size of the aneurysm in the thoracicarch after deployment of the stent graft an extension stent graft may bedeployed intra-luminally via the branch artery to connect into the sidearm.

In the case of grafting into the left subclavian artery the branchartery into which the snare catheter can be introduced is the brachialartery in the left arm.

U.S. Pat. No. 5,387,235 entitled “Expandable Transluminal GraftProsthesis For Repair Of Aneurysm” discloses apparatus and methods ofretaining grafts onto deployment devices. These features and otherfeatures disclosed in U.S. Pat. No. 5,387,235 could be used with thepresent invention and the disclosure of U.S. Pat. No. 5,387,235 isherewith incorporated in its entirety into this specification.

U.S. Pat. No. 5,720,776 entitled “Barb and Expandable Transluminal GraftProsthesis For Repair of Aneurysm” discloses improved barbs with variousforms of mechanical attachment to a stent. These features and otherfeatures disclosed in U.S. Pat. No. 5,720,776 could be used with thepresent invention and the disclosure of U.S. Pat. No. 5,720,776 isherewith incorporated in its entirety into this specification.

PCT Patent Publication Number WO98/53761 entitled “A Prosthesis and aMethod of Deploying a Prosthesis” discloses an introducer for aprosthesis which retains the prosthesis so that each end can be movedindependently. These features and other features disclosed in PCT PatentPublication Number No. WO98/53761 could be used with the presentinvention and the disclosure of PCT Patent Publication Number No.WO98/53761 is herewith incorporated in its entirety into thisspecification.

PCT Patent Publication No. WO 03/034948 entitled “Prosthesis For CurvedLumens” discloses prostheses with arrangements for bending theprosthesis for placement into curved lumens. This feature and otherfeatures disclosed in PCT Patent Publication No. WO 03/034948 could beused with the present invention and the disclosure of PCT PatentPublication No. WO 03/034948 is herewith incorporated in its entiretyinto this specification.

U.S. Pat. No. 6,206,931 entitled “Graft Prosthesis Materials” disclosesgraft prosthesis materials and a method for implanting, transplantingreplacing and repairing a part of a patient and particularly themanufacture and use of a purified, collagen based matrix structureremoved from a submucosa tissue source. These features and otherfeatures disclosed in U.S. Pat. No. 6,206,931 could be used with thepresent invention and the disclosure of U.S. Pat. No. 6,206,931 isherewith incorporated in its entirety into this specification.

Australian Provisional Patent Application N PS3215 entitled “AStent-Graft Fastening Arrangement”, and U.S. patent application Ser. No.10/602,930, filed Jun. 24, 2003 entitled “Stent-Graft Fastening”, andPCT Patent Publication Number WO 2004/002365 disclose arrangements forfastening stents onto grafts particularly for exposed stents. Thisfeature and other features disclosed in Australian Provisional PatentApplication Number No. PS3215 and U.S. patent application Ser. No.10/602,930, filed Jun. 24, 2003, and PCT Patent Publication Number WO2004/002365 could be used with the present invention and the disclosureof Australian Provisional Patent Application Number PS3215 and U.S.patent application Ser. No. 10/602,930, filed Jun. 24, 2003, and PCTPatent Publication Number WO 2004/002365 is herewith incorporated in itsentirety into this specification.

Australian Provisional Application Number PR9617 entitled “ImprovingGraft Adhesion”, and U.S. Patent Application Publication No.US2003-0120332 and PCT Patent Publication Number No. WO03/053287entitled “Stent Graft With Improved Adhesion” disclose arrangements onstent grafts for enhancing the adhesion of such stent grafts into wallsof vessels in which they are deployed. This feature and other featuresdisclosed in Australian Provisional Application Number PR9617, U.S.Patent Application Publication No. US2003-0120332, and PCT PatentPublication Number No. WO03/053287 could be used with the presentinvention and the disclosure of Australian Provisional ApplicationNumber PR9617, U.S. Patent Application Publication No. US2003-0120332,and PCT Patent Publication Number No. WO03/053287 is herewithincorporated in its entirety into this specification.

BRIEF DESCRIPTION OF THE DRAWING

This then generally describes the invention but to assist withunderstanding reference will now be made to the enclosed drawings whichshow a preferred embodiment of the device and the method of deployingthe graft using the device.

In the drawings:

FIG. 1 shows an embodiment of an introducer device according to thisinvention;

FIG. 2 shows an alternative embodiment of an introducer device accordingto this invention;

FIG. 3 shows detail of the proximal end of the introducer deviceaccording to either FIG. 1 or FIG. 2;

FIG. 4 shows a longitudinal cross-sectional view of the proximal endintroducer device shown in FIG. 3 and showing one embodiment of stentgraft retained therein;

FIG. 5 shows a transverse cross-sectional view of a side arm of a stentgraft suitable for the invention particularly showing a diameterreducing tie arrangement;

FIG. 6 shows an embodiment of a stent graft suitable for the presentinvention;

FIG. 7 shows an alternative embodiment of a stent graft suitable for thepresent invention;

FIG. 8 shows an alternative embodiment of a stent graft suitable for thepresent invention;

FIG. 9 shows an alternative embodiment of a stent graft suitable for thepresent invention;

FIG. 10 shows a schematic view of the first stage of deployment of theintroducer device shown in FIG. 1 or FIG. 2 and including a stent graftas shown in FIG. 9 into a thoracic arch of a patient;

FIG. 11 shows a second stage in the process with the auxiliary guidewire snared;

FIG. 12 shows a further stage with a protective catheter passed overauxiliary guide wire;

FIG. 13 shows a further stage with the sheath on the deployment devicewithdrawn partially;

FIG. 14 shows the next stage of deployment with the side arm drawn intothe subclavian artery;

FIG. 15 shows the first stage of release of the stent graft from theintroducer device;

FIG. 16 shows the second stage of release of the stent graft from theintroducer device;

FIG. 17 shows the final stage of release of the stent graft from theintroducer:

FIG. 18 shows a schematic and detailed view of the deployment of a stentgraft of a type as shown in FIG. 8 into a thoracic arch of a patient;

FIG. 19 shows a detailed view of the deployment of a stent graft of atype as shown in FIG. 6 into a thoracic arch of a patient; and

FIG. 20 shows a detailed view of the deployment of a stent graft of atype as shown in FIG. 7 into a thoracic arch of a patient.

DETAILED DESCRIPTION

Now looking more closely at the drawings and in particular FIGS. 1 to 5which show preferred embodiments of deployment devices or introducersaccording to the invention. In each case the same reference numeralswill be used for corresponding components or parts.

It will be seen that the endoluminal deployment device generallycomprises an introducer 1 a comprising a deployment catheter 1 with ahandle 2 at the distal end generally shown as 4. Covering a portion ofthe deployment catheter 1 is a sheath 3 extending proximally from asheath manipulator 7.

At the proximal end 6 of the introducer 1 a is a nose cone 8. The nosecone is fastened to the guide wire catheter 9 which extends from thedistal end 4 of the introducer device to the nose cone. A guide wire 11extends through the guide wire catheter 9. A pin vice 10 locks the guidewire catheter with respect to the deployment catheter 1 at the distalend 2 a of the handle 2.

In the embodiment shown in FIG. 1, proximally of the handle 2 is a “Y”piece 15 in the deployment catheter 1 with a side arm 16 extending fromthe “Y” piece. Extending through the side arm 16 and through a seal 17is an auxiliary catheter 13 with an auxiliary guide wire 14 through theauxiliary catheter 13. A grip and syringe adaptor 12 at the distal endof the auxiliary catheter 13 enables connection of a syringe to flushthe auxiliary catheter 13 as required.

In the embodiment shown in FIG. 2, an auxiliary catheter 13 with anauxiliary guide wire 14 extending through the auxiliary catheter 13extends from the distal end 2 a of the handle 2. A grip and syringeadaptor 12 at the distal end of the auxiliary catheter 13 enablesconnection of a syringe to flush the auxiliary catheter 13 as required.

On the handle 2 is mounted a set of trigger wire release arrangementsgenerally shown as 18 which will be discussed in detail later.

It will be noted that the nose cone 8 has, as particularly shown in FIG.4, a longitudinal notch 28 through which passes the auxiliary catheter13 and auxiliary guide wire 14 so that it extends just beyond the sheath3. This means that once the introducer has been deployed insubstantially the correct position the auxiliary guide wire 14 can beadvanced beyond the nose cone 8 so that it can be snared from the sidebranch artery as will be discussed later.

As can also be seen separately in various embodiments in FIGS. 6 to 10and in a compressed condition partially in FIG. 3 there is a stent graft20 which is retained under the sheath 3 in the region 19 on theintroducer.

The stent graft 20 has a substantially tubular body with a lumen throughit and with a proximal end 21 and a distal end 22. Four differentembodiments of stent graft may be applicable to the present inventionand these are shown in FIGS. 6 to 9. The embodiment shown in FIG. 9 ispartially shown in a compressed condition on the deployment device inFIG. 4. Extending substantially laterally from the tubular body 20 andnearer the proximal end 21 is a side arm 23 again with a lumen throughit which is continuous with the lumen of the tubular body 20. As can beparticularly seen in FIG. 4 when the stent graft 20 is in a compressedstate within the sheath 3, the side arm 23 is directed proximally.

As seen in FIG. 9, the stent graft 20 has zig zag style Gianturco Zstents 24 along its length with a distally extending uncovered zig zagstyle Gianturco Z stent 26. It should be noted that in some embodimentsof the stent graft for placement in the thoracic arch the distallyextending uncovered zig zag style Gianturco Z stent 26 may not bepresent. The side arm 23 also has zig zag Gianturco Z stents 27. Thestents are inside the stent graft 20 at the proximal and distal ends andoutside the stent graft 20 between the proximal and distal ends. Thenumber of zig zag Gianturco Z stents along the length of the tubulargraft 20 will depend upon the length of the stent graft 20.

As can be seen in FIG. 4 and in detail in FIG. 5 the side arm 23 is heldin a diameter reduced condition for deployment by means of diameterreducing ties 29. The diameter reducing ties 29 are lengths of suturematerial which are fastened to the graft material at 30 and are loopedaround a trigger wire 31 on the opposite side of the side arm and pulledtight so that the diameter of the side arm is reduced. When the triggerwire 31 is released as will be discussed later, the loops of thediameter reducing ties are released and the side arm can expand to itsfull size. After release the diameter reducing ties remain fixed to thegraft material of the side arm.

The auxiliary catheter includes a bulge or “acorn” 44 where it passesthrough the side arm 23 with extra diameter reducing ties 46 either sideof it. These diameter reducing ties 46 effectively grip the auxiliaryguide wire catheter either side of the bulge or “acorn”. By thisarrangement the auxiliary catheter cannot be moved with respect to theside arm unless the diameter reducing ties 46 are removed. Thisfacilitates the moving of the side arm by preventing relative movementof the side arm with respect to the auxiliary catheter 12. The extradiameter reducing ties 46 can be released by the same trigger wire 31that is used to release the diameter reducing ties 29.

Also on the side arm 23 are radio-opaque markers 33 which enable theposition of the side arm to be observed by suitable radio-graphictechniques.

The proximal end 21 of the stent graft 20 is retained in a compressedcondition and attached to the guide wire catheter 9 by a releasearrangement 35 and a trigger wire 36 to release the release arrangement35 is also present. Such a retention and release arrangement is depictedin PCT Publication WO 2004/017868 and the disclosure of this patentspecification is incorporated in its entirety herein and for allpurposes

A further trigger wire release arrangement (not shown in FIG. 4) is usedto retain the distal end of the stent graft at the proximal end of thedeployment catheter 1. This distal release arrangement may include acapsule for the exposed stent 26 (see FIG. 9). Such a capsule system isdepicted in PCT Publication WO 98/53716. The use of a distal capsulesystem and a deployment system to release an exposed stent is describedin United States of America Provisional Patent Application Ser. No.60/392,667 and the disclosures of those patent specifications areincorporated in their entirety herein and for all purposes.

It will be noted that the auxiliary catheter 13 and the auxiliary guidewire 14 pass through the lumen of the stent graft 20 as well as thelumen of the side arm 23 and then out through the notch 28 in the nosecone 8.

The trigger wire release arrangements 18 on the handle 2 includes threetrigger wire release mechanisms. A first trigger wire release mechanism40 is used to release the distal stent graft release mechanism viatrigger wire 37, a second trigger wire release mechanism 41 is used torelease the proximal end stent graft release mechanism 35 via triggerwire 36 and the third trigger wire release mechanism 42 is used to pullthe trigger wire 31 which releases the diameter reducing ties 29. Thetrigger wire release mechanisms are operated in the order discussed aswill be explained also later with respect to the various stages ofdeployment according to one embodiment of the invention. In someembodiments of the invention there may be only two trigger wire releasemechanisms such as where the proximal and distal ends of the stent graftare retained by the same trigger wire.

Various embodiments of stent graft suitable for use with the presentinvention will now be discussed with reference to FIG. 6 to 9. In eachcase the same reference numerals will be used for correspondingcomponents or parts.

Each of the stent grafts 20 has a tubular body of a biocompatible graftmaterial and zig zag style Gianturco Z stents 24 along its length with adistally extending uncovered zig zag style Gianturco Z stent 26. Itshould be noted that in some embodiments of the stent graft forplacement in the thoracic arch the distally extending uncovered zig zagstyle Gianturco Z stent 26 may not be present. This may be so, forinstance, when the stent graft 20 is a proximal portion of a compositestent grafting system. The use of a composite stent grafting system isdescribed in PCT publication WO 2004/017867 and the disclosures of thispatent specification is incorporated in its entirety herein and for allpurposes.

The stents are inside the stent graft 20 at the proximal and distal ends21, 22 and outside the stent graft 20 between the proximal end 21 andthe distal end 22. The number of zig zag Gianturco Z stents along thelength of the tubular graft 20 will depend upon the length of the stentgraft 20. Normally the zig zag Gianturco Z stents are spaced apart toallow a degree of flexibility of the stent graft so that it can moreeasily fit the shape of a vessel into which it is deployed.

In each case the stent graft includes a fenestration but the treatmentof the fenestration varies.

In FIG. 6 the fenestration 75 has a graft material tube 77 fastenedaround its periphery and extending within the stent graft and towardsthe distal end 22. The graft material tube 77 includes an external zigzag Gianturco Z stent 76. When a side arm stent graft is deployedthrough the fenestration 75 into the graft material tube 77 it is intothe region of the external zig zag Gianturco Z stent 76 that sealingoccurs. The end 79 of the graft material tube 77 is cut off at an angleand fastened by stitching 80 to the stent graft wall 20. The size of thefenestration 75 is preferably somewhat larger than the size of thebranch vessel to allow for a degree of misalignment. For instance thefenestration may have an oval shape. The dotted line 80 shows how theauxiliary guide wire catheter passes through the graft material tube 77and fenestration 75.

In FIG. 7 the fenestration 85 has a graft material tube 87 fastenedaround its periphery and extending within the stent graft and towardsthe proximal end 21. The graft material tube 87 includes an external zigzag Gianturco Z stent 86. When a side arm stent graft is deployedthrough the fenestration 85 into the graft material tube 87 it is intothe region of the external zig zag Gianturco Z stent 86 that sealingoccurs. The end 89 of the graft material tube 87 is fastened bystitching 90 to the stent graft wall 20. The size of the fenestration 85is preferably somewhat larger than the size of the branch vessel toallow for a degree of misalignment. For instance the fenestration mayhave an oval shape. The fenestration 85 may also have a reinforcementring of Nitinol or similar resilient wire around its periphery. Thedotted line 80 shows how the auxiliary guide wire catheter passesthrough the graft material tube 87 and fenestration 85. At 88 theauxiliary catheter passes through an aperture in the graft material tube87 which aperture is preferably self sealing so that after removal ofthe auxiliary guide wire catheter leakage of blood does not occur. Thismay be achieved by spreading apart the fibres of the graft material tubeto allow the auxiliary catheter to pass through rather than cutting themat 88. Alternatively some form of flap valve may be used.

In an alternative arrangement the auxiliary catheter may have a zig zagconfiguration and pass up through the stent graft 20 and enter the graftmaterial tube 87 at its end 89 and then exit through the fenestration85.

In FIG. 8 the stent graft 20 merely has a fenestration 70 with areinforcement ring 73 of Nitinol or similar resilient wire around itsperiphery. When a side arm stent graft is deployed through thefenestration into the stent graft 20 sealing occurs around the peripheryof the fenestration. The size of the fenestration 70 is preferablyslightly smaller than the size of the side arm stent graft to be placedinto the branch vessel to allow for sealing. In this embodiment stentgraft 20 includes a scalloped end 71 to allow the stent graft to beplaced over the adjacent carotid artery. Such a scalloped end may alsobe used with the other embodiments of stent graft. The dotted line 80shows how the auxiliary guide wire catheter passes through the stentgraft 20 and fenestration 75.

In FIG. 9 the fenestration 92 has a graft material tube 23 fastenedaround its periphery and extending from the stent graft. Thefenestration 92 may also have a reinforcement ring of Nitinol or similarresilient wire around its periphery. The graft material tube 23 includesone or more external zig zag Gianturco Z stents 27. The dotted line 80shows how the auxiliary guide wire catheter passes through the graftmaterial tube 23 and fenestration 92. The side arm 23 includesradio-opaque markers 33 to assist with placement.

The various stages of deployment of one embodiment of the stent graft 20into the thoracic arch of a patient will now be discussed with referenceto FIGS. 10 to 17. The deployment device can be the type shown in eitherFIG. 1 or FIG. 2.

The thoracic arch region of a patient generally comprises an ascendingaorta 50 extending from an aortic valve 51 of the heart of the patient,then over the thoracic arch 52 to the descending aorta 53. From thethoracic arch three main arteries extend. These are the innominateartery 54, the left carotid artery 55 and a subclavian artery 56. Thisembodiment of the invention will generally be discussed with referenceto deployment of a stent graft with a side branch into the aorta andleft subclavian artery but the invention is not so restricted.

A stent graft may be necessary in the aortic arch region when ananeurysm 57 in the aorta extends up the aorta to such an extent thatthere is insufficient patent aortic wall to provide good sealing for astent graft distally of the left subclavian artery 56. It is desirablein such circumstances to extend the stent graft to seal onto good arterywall at least between the left carotid artery 55 and the left subclavianartery 56.

The invention is not limited to this particular application but will bediscussed in relation to this particular application.

As can be seen in FIG. 10 the introducer 1 a has been introduced intothe aorta normally via an incision into the femoral artery over a guidewire 11. The guide wire 11 has been deployed down towards the aorticvalve 51. Once the introducer is in position the auxiliary guide wire 14is extended beyond the nose cone 8 of the introducer until it isadjacent the left subclavian artery. A suitable radio-graphic tip may beprovided on the guide wire to assist with determination of its location.

An incision can then be made into the brachial artery of the left armand a snare catheter 60 introduced into the brachial artery and via thatto the left subclavian artery and this snare catheter has a loop 61 atits end which can then be used to snare the guide wire 14. The snare isused to grip and pull the flexible guide wire 14 into the leftsubclavian artery and out through the brachial artery.

In the next stage shown in FIG. 11 the introducer 1 a is advancedproximally over the guide wire 11 with the auxiliary guide wire 14 stillextending into the left subclavian artery. The introducer is advanceduntil the nose cone is adjacent the left subclavian artery and thesheath 3 is just distal of the opening of the artery into the thoracicarch.

As can be seen in FIG. 12 a protective catheter or sleeve 62 is deployedonto the auxiliary guide wire where it exits from the brachial arteryand is then slid over the auxiliary guide wire 14 from the brachialartery end to protect the junction 57 of the left subclavian artery withthe thoracic arch during the subsequent steps. The protective catheteror sleeve 62 and the auxiliary guide wire 14 are then locked together sothat they can be used to pull the side arm 23 of the stent graft intothe left subclavian artery 56.

As can be seen in FIG. 13 the sheath 3 of the introducer 1 a has beenpartially withdrawn so that the stent graft 20 retained by the sheath 3has expanded but the retention arrangement 35 still holds the proximalend 21 of the graft in a restrained condition. The side arm 23 is alsoreleased from the sheath but still held in a retracted condition bydiameter reducing ties 29. It will be noted that at this stage thedistal end 22 of the stent graft is still retained within the sheath 3.

As shown in FIG. 14, the introducer 1 a is then moved further proximallywhile pulling on the protection catheter 62 and guide wire 14 so thatthe side arm 23 of the stent graft 20 is pulled into the left subclavianartery 56.

As shown in FIG. 15 the sheath 3 is then pulled further back so that thedistal end of the graft 20 is released from the sheath 3 and then thedistal trigger wire release mechanism 40 (see FIG. 1) can be released torelease the external zig zag stents 26 so that they expand against thewall of the descending aorta 53.

Next as shown in FIG. 16 the proximal end 21 of the graft 20 is releasedby releasing the retention mechanism 35 (see FIG. 1) by pulling on thetrigger wire release mechanism 41 which pulls out trigger wire 36.

Finally as shown in FIG. 17 the diameter reducing ties are released bypulling on the trigger wire release mechanism 42 (see FIG. 1) whichpulls the trigger wire 31.

The auxiliary guide wire 14 can then be retracted into the introducer 1a and the introducer removed from the aorta to leave the stent graft 20deployed in the aorta with the side arm 23 deployed into the leftsubclavian artery 56.

FIG. 18 shows a schematic and a detailed view of the deployment of astent graft as shown in FIG. 8 into a thoracic arch of a patient. Afterthe introducer is deployed into the thoracic arch and the auxiliaryguide wire snared as shown in FIGS. 10 and 11 the introducer is furtheradvanced proximally over the main guide wire 11 until the fenestration70 (see also FIG. 8) is adjacent the subclavian artery 56. It will benoted that at this stage the scallop 71 at the distal end 21 of thestent graft 20 is positioned around the adjacent carotid artery 55 so asnot to occlude it. This arrangement enables the distal end 21 of thestent graft 20 to have a larger landing zone in the thoracic arch whilenot occluding the carotid artery. A separate balloon expandable stentgraft 72 can then be deployed brachially and through the subclavianartery over the auxiliary guide wire 14 so that its proximal end 74enters the fenestration 70 and then it can be balloon expanded so thatthe end 74 is in effect crimped around the fenestration 70 to securelyretain the stent graft 72 in the fenestration 70.

FIG. 19 shows a detailed view of the deployment of a stent graft asshown in FIG. 6 into a thoracic arch of a patient. After the introduceris deployed into the thoracic arch and the auxiliary guide wire snaredas shown in FIGS. 10 and 11 the introducer is further advancedproximally over the main guide wire 11 (see FIG. 11) until thefenestration 75 (see also FIG. 6) is adjacent the subclavian artery 56.A separate balloon expandable or self expanding stent graft 94 can thenbe deployed brachially through the subclavian artery over the auxiliaryguide wire 14 so that its proximal end 96 enters the fenestration 75 andthen it can be allowed to expand or be balloon expanded so that the endis expanded within the graft material tube 77 to seal the side arm stentgraft 94 into the main stent graft 20.

FIG. 20 shows a detail view of the deployment of a stent graft as shownin FIG. 7 into a thoracic arch of a patient. After the introducer isdeployed into the thoracic arch and the auxiliary guide wire snared asshown in FIGS. 10 and 11 the introducer is further advanced proximallyover the main guide wire 11 until the fenestration 85 (see also FIG. 7)is adjacent the subclavian artery 56. A separate balloon expandable orself expanding stent graft 98 can then be deployed brachially throughthe subclavian artery over the auxiliary guide wire 14 so that itsproximal end 99 enters the fenestration 75 and then it can be allowed toexpand or be balloon expanded so that the end is expanded within thegraft material tube 87 to seal the side arm stent graft 98 into the mainstent graft 20.

Throughout this specification various indications have been given as tothe scope of this invention but the invention is not limited to any oneof these but may reside in two or more of these combined together. Theexamples are given for illustration only and not for limitation.

Throughout this specification and the claims that follow unless thecontext requires otherwise, the words ‘comprise’ and ‘include’ andvariations such as ‘comprising’ and ‘including’ will be understood toimply the inclusion of a stated integer or group of integers but not theexclusion of any other integer or group of integers.

1. A deployment system for a stent graft to be deployed into an internallumen of a patient, the deployment system comprising in combination anintroducer and a stent graft retained on the introducer, a catheterassociated with the introducer extending through at least a portion ofthe stent graft, the at least a portion of the stent graft comprisingdiameter reducing ties with an associated trigger wire and trigger wirerelease mechanism, the diameter reducing ties being used to hold theleast a portion of the stent graft in a diameter reduced conditionagainst the catheter associated with the introducer, the catheterassociated with the introducer comprising a bulge where it passesthrough the least a portion of the stent graft with the diameterreducing ties either side of the bulge whereby the diameter reducingties and bulge effectively grip the catheter associated with theintroducer and the least a portion of the stent graft such that thecombination move together.
 2. A deployment system for a stent graft asin claim 1 wherein the catheter associated with the introducer comprisesan auxiliary catheter.
 3. A deployment system for a stent graft as inclaim 2 wherein the at least one portion of the stent graft comprises aside arm of the stent graft.
 4. A deployment system for a stent graft asin claim 2 wherein the auxiliary catheter passes through the side arm ofthe stent graft and the side arm is retained by the diameter reducingties in the diameter reduced condition and the bulge is on the auxiliarycatheter where it passes through the side arm.
 5. A deployment systemfor a stent graft as in claim 1 wherein the introducer comprises aproximal end intended to be deployed within a patient in use and adistal end intended to remain outside the patient, a main guide wirecatheter extending from a proximal end to a distal end, a nose cone atthe proximal end of the guide wire catheter and a sheath.
 6. Adeployment system as in claim 5 wherein the catheter associated with theintroducer comprises an auxiliary catheter and the auxiliary catheterextends out between the nose cone and the sheath.
 7. A deployment deviceas in claim 6 wherein the nose cone includes a longitudinal notch on anouter surface thereof to allow the auxiliary catheter to exit the sheaththerealong.
 8. A deployment system for a stent graft as in claim 5wherein the stent graft comprises a tubular body with a lumentherethrough, the stent graft being retained on the main guide wirecatheter distally of the nose cone with the main guide wire catheterpassing through the lumen of the stent graft.
 9. A deployment system asin claim 8 including a retention arrangement for the stent graft on theintroducer, the stent graft comprising a proximal end and a distal endand the retention arrangement temporarily retaining the proximal end andthe distal end of the stent graft onto the introducer and the retentionarrangement including trigger wires and trigger wire release mechanismsto release the retention arrangement.
 10. A deployment device as inclaim 3 wherein the stent graft and side arm on the stent graftcomprises self-expanding stents and a tubular biocompatible graft.
 11. Adeployment device as in claim 1 wherein the catheter associated with theintroducer comprises a guide wire therein and the guide wire can bemoved independently of the catheter.
 12. A deployment device as in claim2 wherein the auxiliary catheter comprises an auxiliary guide wiretherein and the auxiliary guide wire can be moved independently of theauxiliary catheter.